The present invention relates to image processing.
An electronic image, such as a digital image, can be represented by an array of closely packed pixels that are basic picture elements. Each pixel represents a local portion of the image and alone or together with other pixels, determines graphical attributes for the local portion. The graphical attributes can include color, gray-level, luminosity or transparency. Electronic images can be generated by graphical software applications or electronic devices such as scanners or digital cameras. The graphical software applications include presentation, animation, painting and design applications. The generated image can be further processed by the same or another device or application. During image processing, graphical attributes can be adjusted at the pixels of the image to achieve various visual effects that include adjustments to brightness, contrast or color.